The ongoing miniaturization of hand-held multi-media devices such as Personal Digital Assistants (PDAs) or mobile phones in recent years appears to be only bounded by the perceptual limits of the human user. This particularly applies to the design of the User Interfaces (UIs) of hand-held devices, such as for instance displays or touch-screen displays, with a remarkable trend to increase the relative area of the hand-held device that is consumed by its UI. Portrayal of content on such UIs can be further improved by allowing for a change of the orientation of the UI with respect to the hand-held device said UI is integrated in. Such a change of the orientation of the UI may for instance take the shape of a rotation of the UI with respect to the hand-held device, so that said hand-held device can for instance be used in both horizontal and vertical position.
When the orientation of a UI is changed, the logic that controls the UI has to be adapted to the change of orientation.
FIG. 1a exemplarily depicts a mobile phone 1 with a rectangular UI 2 of size a×b. In the left figure of FIG. 1a, an image is displayed on the UI 2, for instance a snapshot taken by the user of a different mobile phone and sent to the user of the mobile phone 1 via the Multimedia Messaging Service (MMS). To view the snapshot properly, either the user of mobile phone 1 would have to rotate his mobile phone 1 by 90° clockwise, or the orientation of the UI would have to be rotated by 90° clockwise, as depicted in the right figure of FIG. 1a. Such a rotation of the orientation of the UI can be initiated by the user by pressing a key 3 on his mobile phone 1 or by browsing through the menu of his mobile phone 1 to find the menu option that allows for the rotation of the UI orientation. Rotation of the orientation of the UI 2 is performed in software, for instance by the UI controller of the mobile phone 1.
FIG. 1b shows a second example of improved portrayal of images on a UI 2 of a mobile phone 1 when rotating the orientation of the UI 2. A typical landscape image is to be viewed on the UI 2 of the mobile phone 1 as shown in the left figure of FIG. 1b. Due to the limited width of the UI 2, the landscape image is either re-sized to fit the width b of the UI 2, as shown in the upper left figure of FIG. 1b, or only a part of the entire image is displayed on the UI 2 by fitting the height of the image to the height of the display and inserting a scroll bar 4, so that the remaining parts on the right side of the image can be explored by the user of the mobile phone 1 by scrolling (see the lower left figure of FIG. 1b). Portrayal is improved by rotating the orientation of the UI 2 by 90° clockwise, for instance by pressing a key 3 of the mobile phone 1, that switches between portrait orientation (as on the left of FIG. 1b) and landscape orientation (as on the right of FIG. 1b). The full-size image then can be viewed under optimum exploitation of the dimensions of the UI 2.
In prior art devices, the orientation of a UI can be changed by pressing a hard key of the device, for instance a portrait/landscape key 3 as in the example of FIG. 1b. However, due to the limited size of hand-held devices, additional hard keys are generally difficult to place on the device, and assigning an already existing hard key additional functionality, for instance that the hard key has to be pressed for a longer duration to call the additional functionality, may distract the user of the device.
In further prior art, the change of the orientation of the UI is implemented as a menu option of a display menu. The user of the device then has to browse the devices menu and find the corresponding entry in order to change the orientation of the UI, which is a time-consuming and annoying task especially when the orientation of a UI has to be frequently changed. Furthermore, the unskilled user of the device may not be aware of the possibility to change the orientation of the UI or may get lost in the menu when searching for it.
A further prior art approach to cause the change of the orientation of a UI uses motion sensors in the device to determine if the device itself is rotated by a user. For instance, in the example of FIG. 1b, when the user rotates the mobile phone 1 with the image being displayed according to the upper or lower left figure by 90° clockwise, the rotation is sensed by the mobile phone 1, and the orientation of the UI 2 is automatically switched from portrait mode to landscape mode (see the right figure of FIG. 1b), without any further user interaction like pressing a hard key or similar. This approach, however, deprives the user of his freedom to choose in which orientation of the UI 2 he prefers to watch an image. Furthermore, this method may become unstable in a mobile environment where the mobile phone 1 is subject to frequent relocation and shocks.